1. To run someone down from behind and tackle them, much as a quick bird of flight would chase down a dog.
2. To screw over or get screwed over, often by ones own close friends. See Biddle.
3. To harass to no end by the repeated utterance of a nonsensical phrase.

1. "Did you see last night? Addison completely bird dogged Derek in the nuts even though he's crippled!"
2. "That Justin kid, I bird dogged him pretty bad last night, I think he wants to kill me."
3. "Damnit Berman! Stop bird dogging!"

A sudden, unexpected tackle.
Usually in parking lots, bed rooms, parties, or near pools.
sometimes a bird dog is a friendly tackle, other times meant to do harm.
The most famous bird dog is performed in the movie "Old School" by Will Ferrell when he bird dogs a man into a fountain.. this is where the term originated.

After Bridgett stole Steve's seat, he was forced to Bird Dog her in order to get it back.